Cigarette paper



Patented Sept. 22, 1953 CIGARETTE PAPER Milton 0. Schur, Asheville, andRobert M. Levy,

Brevard, N. 0., assignors to Eeusta Paper Corporation, a corporation ofDelaware No Drawing. Application March 7, 1952, Serial No. 275,462

4 Claims. (Cl. 13115) Our invention relates to cigarette paper and moreparticularly to improving the ashing properties of cigarette paper whenburned as the wrapper on a cigarette.

A desirable paper ash is one that has a minimum of carbonized orincompletely burned residue, has a grayish-white color, adheres to thetobacco ash and thereby avoids dropping of ashes on the smokersclothing, but is nevertheless easily flickable at the will of thesmoker.

In U. S. Patent No. 2,580,568, issued January 1, 1952, to Robinson E.Matthews and Ward D. Harrison, there is disclosed a cigarette paperhaving the above-mentioned desirable ashing properties, which areobtained by incorporating in the paper approximately 0.1% to 1% ofammonium phosphate. An improvement in that connection is disclosed inour U. S. Patent No. 2,580,610, issued January 1, 1952, which comprisesincorporating in the cigarette paper, in addition to the ammoniumphosphate, a very minute amount of phosphoric acid.

We have now discovered from further research in this field that theabove described desired type of ash, and which has even more permanentproperties, can be obtained by using in place of the ammonium phosphate,a difierent chemical compound, namely guanylurea phosphate. Thiscompound does not require the addition of phosphoric acid or any othersubstance to improve the permanency of the desired ashing properties andthus alone fulfllls all of the ashing requirements.

In accordance with the present invention, an aqueous solution of theguanylurea phosphate is prepared and incorporated in the cigarette paperweb running on the paper machine, at a point prior to the final dryingrolls. A convenient form of application is by means of the conventionalsize press, located near the middle of the drying section of the papermachine, so that the aqueous composition will be imparted to thepartially or completely dried paper sheet.

A typical but non-limiting formula for the aqueous composition,applicable in the size press, is as follows:

Formula Guanylurea phosphate lbs 65 Water to. make gals 1000 2 amountmay be varied within the approximate limits of 0.25% to 1.5%.

The above-indicated range is adjusted between two extremes, namely, amaximum or upper limit at which the guanylurea phosphate will begin tofireproof the cigarette paper, which of course, should be avoided tomaintain the desired normal burning rate of the paper, and minimum orlower hmit which gives a less desirable ash and a lower degree ofstability. Th range indicated falls between these extremes and has beenfound satisfactory in actual operation. The specific amount given underFormula above is advantageous in certain instances and has givenexcellent results.

An illustrative commercial procedure for using the present invention inthe manufactur of cigarette paper is as follows:

A sheet of cigarette paper was formed in the conventional manner from afurnish comprised of beaten flax pulp and calcium carbonate filler. At apoint in the drier where the water content of the paper was about equalin weight to the dry Weight of the fiber and the filler, the paper wasrun through a size press and impregnated with a solution preparedaccording to the above formula. A weight of solution about equal to theweight of the dry contents of the paper was imparted to the paper, andthe paper was then completely dried by passage over drying cylinders inthe conventional manner.

The use of guanylurea phosphate as an ashing chemical is xtraordinary inthat cigarette paper treated with this compound when stored at relativehumidity for a period of thirty days still retains its fine ashingcharacteristics.

The stable ashing characteristic of guanylurea phosphate is of specialsignificance when the cigarette paper is on the cigarette, because thecigarette tobacco is moist and that condition accentuates the usualinstability of the ashing properties of the paper. Cigarettes rolled inthe paper, prepared as above described, burned so as to leave fine,discontinuous flakes of paper ash, which closely adhered to the tobaccoash, and these cigarettes upon storage retained their fine ashingproperties, when burned.

The nller commonly used in cigarette paper to regulate the porosity, andhence the rate at which it burns on the cigarette, is calcium carbonate.It is ordinarily added to the flax pulp furnish in an amount sufficientto give a filler content of about 20%25% in the finished paper, and itconstitutes the principal ash-forming constituent in the cigarettepaper.

Various modifications and changes may be made in the foregoing process,materials and products, without departing from the spirit and scope ofour invention as defined in the appended claims.

We claim:

1. A combustible cigarette paper containing cellulosic fibers, calciumcarbonate filler, and impregnated throughout with approximately 0.25% to1.5% guanylurea phosphate, based on the dry weight of the cigarettepaper.

2. A combustible cigarette paper containing cellulosic fibers, calciumcarbonate filler, and impregnated throughout with approximately 0.75%guanylurea phosphate, based on the dry weight of the cigarette paper.

3. A combustible cigarette paper containing flax fibers, calciumcarbonate filler, and impregnated throughout with approximately 0.25% to1.5% guanylurea phosphate, based on the dry weight of the cigarettepaper.

4. A combustible cigarette paper containing flax fibers, calciumcarbonate filler, and impregnated throughout with approximately 0.75%guanylurea phosphate, based on the dry weight of 5 the cigarette paper.

MILTON O. SCHUR. ROBERT M. LEVY.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 2,305,035 Rosser Dec. 15, 1942 2,488,034 Pingree et al. Nov.15, 1949 15 2,580,611 Schur et a1. Jan. 1, 1952 FOREIGN PATENTS NumberCountry Date 476,043 Great Britain Nov. 29, 1937 638,434 Great BritainJune 7, 1950

1. A COMBUSTIBLE CIGARETTE PAPER CONTAINING CELLULOSIC FIBERS, CALCIUMCARBONATE FILLER, AND IMPREGNATED THROUGHOUT WITH APPROXIMATELY 0.25% TO1.5% GUANYLUREA PHOSPHATE, BASED ON THE DRY WEIGHT OF THE CIGARETTEPAPER.